1. Field of the Invention
The invention relates to a tube connecting device, more particularly to an improved tube connecting device which can be easily installed and which provides firm and stable connection between two tubes.
2. Description of the Related Art
Referring to FIG. 1, a conventional tube connecting device is shown to comprise first and second tubular connector members (1, 5), each of which is connected to one end of a corresponding tube (shown in phantom lines). The first connector member (1) has a receiving end portion (2) and two opposite pairs of pivot ears (3) that project outwardly from the latter. A radial opening (4) is formed between each pair of pivot ears (3). The second connector member (5) extends into the receiving end portion (2) and has an outer surface which is formed with an annular peripheral groove (6). The peripheral groove (6) has an inwardly curved inner end and is registered with the radial openings (4). The tube connecting device further includes a pair of press arms (7), each of which having one end mounted pivotally to a respective one of the pairs of pivot ears (3) and formed with a cam face (8). When the press arms (7) are pivoted to a locking position, the cam faces (8) extend into the peripheral groove (6) via the respective radial opening (4) so as to press against the second connector member (5) at the peripheral groove (6), thereby securing the second connector member (5) to the first connector member (1).
Note that in the above described conventional tube connecting device, the pressing force that is applied by the cam faces (8) is used to secure the second connector member (5) to the first connector member (1). However, no retaining device is provided so as to prevent untimely movement of the press arms (7). Therefore, untimely disengagement between the cam faces (8) and the peripheral groove (6) can occur, thereby resulting in the untimely disengagement of the first and second connector members (1, 5)
In order to overcome the above mentioned drawback, the construction of the conventional tube connecting device shown in FIG. 1 has been modified, as best illustrated in FIG. 2. The first connector member (1') is provided with a pair of opposite retaining projections (9). Each of the retaining projections (9) is formed with a longitudinal through bore (11). Each of the press arms (7') is provided with an opening (12) to permit a corresponding one of the retaining projections (9) to extend therein when the press arms (7') are in the locked position Each of the press arms (7') is further provided with a hook end (13) and a fastening ring (14) provided on the hook end (13).
Referring to FIG. 3, the retaining projections (9) extend into the openings (12) in the press arms (7') after the press arms (7') have been pivoted to the locking position. One end of each of the fastening rings (14) is then extended into the through bore (11) of a respective one of the retaining projections (9), thereby retaining the press arms (7') on the first connector member (1') so as to prevent untimely movement of the former.
Note that although untimely movement of the press arms (7') can be prevented, the act of inserting one end of the fastening rings (14) into the through bore (11) of the respective retaining projection (9) can complicate the installation of the tube connecting device. The conventional tube connecting device shown in FIGS. 2 and 3 is thus inconvenient to use.